Amalgamation
by Zimtard
Summary: [One-off] Episode 24 AU. Rated T for swearing and very mild body horror. NO SHIPPING. AU where the matsus become an Amalgamate. As in Undertale Amalgamates. I dunno what other kinds there is but... yeah. I feel terrible for doing this to my sons. EDIT: Second chapter is a newer, updated version!
1. Chapter 1

The entire day, Osomatsu had felt off. He should have been happy for his brother Choromatsu and that he was moving out, but something felt wrong. Oso knew this was not supposed to happen with everything inside him. The mix of emotion had made him sick to the core. He felt like he was starving, even though that was normal for him, being the pig that he is, it still hurt like hell. His head spun like crazy. Everything just made him feel sick. Osomatsu knew getting very upset or stressed could upset your stomach, but he never expected anything like this. And that had only been in the morning.

(Time skip, after most of episode 24. When Karamatsu drags Osomatsu outside.)

"Osomatsu, what the fuck where you thinking?" The words stung Oso's ears as Kara yelled at him. Osomatsu stood there. Nothing. All that he did was avoid eye contact as his breathing got heavier. It became a challenge to breathe. Karamatsu looked concerned. "B-Buraza... Are you okay?" And just like that, Osomatsu had started to melt. Shakily raising a hand to his cheek to feel what was happening to him. His entire body shook as he started coughing and hacking. "Osomatsu, please, Are you okay!?" Karamatsu's voice was muffled as Osomatsu started to cry, he could see Kara was crying, too. "N-... o..." Oso's voice came out raspy as he struggled to hold up his own weight. Karamatsu had lifted Osomatsu on his back and ran into the house. He had set Oso down on the floor, trying to keep him together. The melting started to get faster and faster. Karamatsu panicked. "It... It's o-.. kay..." Osomatsu tried to help. Karamatsu was sobbing extremely hard. "N-No it's not!" Karamatsu tried to keep his older brother together, finding out that it was a lost cause. He tries to turn away from his brother and forget what was happening. There's no way he could help. All Kara does, though, is cry. His sobs stopped as he felt himself being grabbed from behind. It was Osomatsu, trying to comfort him. "sor...ry.." The word made Kara's heart stop for a moment. All that could be heard is the two brothers choking on their own breath. Kara just sat there, not knowing what to do. After a minute, Kara tried to move away so He could look at his brother again. But then it hit him like a bullet. Osomatsu had melted onto him. He could feel himself starting to melt away just like his brother. He tried to call out for one of the other brothers. No noise came out of his mouth other than a whimper. But in an instance, Jyushimatsu was in the room.

Jyushi's normal large smile had twisted and turned into a horrified frown. "Nii-san? W... What happened?" The yellow matsu stood there in shock. Jyushimatsu dashed over to the pile of neet in front of him and tried to hold them together. No matter how much Oso and Kara tried to object, Jyushi held on tight. He could see his brothers had started to melt into him. Jyushimatsu's smile made a faint return. Jyushimatsu started to sob, knowing there is no way out now. At least he knew he'd be with his brothers.

The remaining three brothers ran into the room, once hearing the fifth brother's cries. Choromatsu let out a girly shriek as Jyushimatsu held onto Oso and Kara. Ichimatsu had immediately ran over to help Jyushi, Choro and Totty following shortly after. "N..o" "Pl-ea...se" "S-sto..p" These words kept repeating. The 3rd, 4th, and 6th brother kept trying to help the giant mass that was their brothers. When the three realized they were too hard to keep together, it was too late. They were already together.

The pile of matsus tried to prop itself up on it's arms. No success. Low moans and grumbles were the only thing that filled the house. Other than that, the entire place was silent. All six brothers were trying to help each other navigate in this new "form" they were stuck in. Arms and legs tried to move in all sorts of directions. The six eventually gave up on going their own way, all deciding to attempt to stand on their now four legs. Six arms pushed on the floor, helping the giant matsu up. They had knocked over some things, but still succeeded. Matsuzo and Matsuyo came in to see what was happening. Little did they expect to see their children as one malformed beast.


	2. REMADE VERSION

**A/N: Please forgive me if this rewrite sucks. It's 7:14 AM and I haven't slept yet and decided to remake this on a whim.**

The day was colder than usual. Osomatsu had a bad feeling from the start, not just that something bad would happen, but that something was off with _himself._ The eldest brother had just pushed it off as a cold or the like, he'd just take some over-the-counters and move on. At that, he was still sick to the core, feeling off with every step he took. He felt starved and fatigued, even if he normally was a bit of a pig. Everything seemed to spin as well as a headache that never seemed to go away. Even then, he still had some other struggles mentally. Choromatsu had announced that he'd, well, be moving out. For some reason Osomatsu just... couldn't handle that. He should support his brother's choices, but something burned in him that wouldn't let go of his younger sibling. No matter how hard he tried. Osomatsu knew that getting worked up with stress could make you feel sick, but never to this extent. The entire day even the brothers would say he seemed different.

 **-The same time skip as last version, right when Kara drags oso outside.-**

"What the actual fuck were you thinking!? You cant just punch Jyushimatsu like that!" Karamatsu's words rang through Osomatsu's ears. They were too sore for him to pay attention to his younger brothers words. He could barely think as the second son stared angrily, waiting for an excuse. "Are you paying attention!?" Karamatsu's yelling only made it worse. A headache rang through Osomatsu's head, too much to bare. All he knew is that Karamatsu was too loud. His voice wasn't even able to make out at this point. It was becoming harder for the eldest to breathe. He started to cough and hack, avoiding eye contact most of the time. But through sickly, half-lidded eyes, Osomatsu saw his sibling's face change. He looked... confused. And... scared... "N...Nii-san... What's g-going on...?" Karamatsu seemed horrified while his brother just stood there unknowingly. Something did feel even weirder than it already did, though. He reached his hand up to his face to feel whatever was going on. The last thing the oldest Matsuno would expect was that he was literally **_melting._** A shock of fear sprang through him as he looked up to Karamatsu as if he could help somehow. The second son panicked. "A-Ah! I... I'll take you inside! Th-The others have to know... something... ri-ight?" Karamatsu choked as he tried to pull on Osomatsu's arm to bring him inside. Wobbling, Osomatsu flopped onto Karamatsu's back as if he was getting a ride. He was in too much pain to move on his own, anyway. "Ka-ara...!" the older croaked out with an unusually raspy voice. He was melting to the point he was sliding off of Karamatsu's back slightly. Kara burst through the door and tried to get to the room where the others were. A shock of pain stuck him instead, sending him onto his hands and knees. A quick self-examination showed that the two brothers were actually melting together. Osomatsu realized this too and tried to seperate from Karamatsu. It didn't work, only causing the two more pain. Mumbled voices could be heard from the two conjoined brothers. "They've... out there... long time... check..." It didn't take long for this to turn into worrying for the reaction of whoever would come through.

Through four eyes the two could make out two colors; pink and green. It was obvious which two were going to check on them. The only thing heard was a loud thump. Out of sheer shock, Todomatsu had dropped his phone on the floor. Choromatsu stood there speechless as the two fused sextuplets sat there staring up with half lidded glares. Totty noticed the melting and instantly moved in to try and help them. Pushing on the pile of fading flesh, he tried to mold them back to normal. Choromatsu had instinctively followed along with the youngest, pushing up on Osomatsu, trying to fix him. The fused two only let out a few words for what it seemed a hundred times. "No..." "Stop..." "Unsafe..." "Please..." kept going on over and over. The stubborn two did not listen though, and ended up becoming a part of the malformation. The shock of pain instantly caused Todomatsu to yelp, causing a worried Jyushimatsu and Ichimatsu to come in.

The two, just like the last, were absolutely speechless. Tears started to instantly fall down Jyushimatsu's face as he rushed head-on into the neet pile trying to help them. Jyushi tried to push the 4 out the door, and hopefully, in time, to Dekapan's to see if he could help in any way. After telling Ichi his plan the two had tried to lift the group. Even for the two of them, the task was too much to handle. The same warnings as before were given, sounding more conjoined at this point. " ** _St-o...p. St...op... Stop-p... St..o...p.."_** The brothers cried out, trying to alert the two rescuers. Just as before, stubborn matsus don't listen. They're eventually crushed under the pile's weight and are forced to give up. Both of them sat silently as they were already, just barely, becoming a part of the amalgamation. They sobbed as they slowly faded in.

 _ **"H,...ghh.,.."**_

The six were together. A big, goopy, crying pile of neet. The beast of a Matsuno attempted to hoist itself up to where it was standing. Six arms weakly pushed in all directions as legs followed suit. After a few tries, the monster finally agrees on a direction. Propping itself on a wall, the giant sextuplet tries to stand. _**"Uh...h.,uh..."**_ It grunts as it gets on it's near centipede-like stance. They all hear a slam as the matsu turns to see what turns out to be the shocked faces of their parents.


End file.
